What is error code 08501?

I'm trying to connect to my Joomla MySQL database on my web hosting service and receive, "Connecton Refused (code 08501)

So, I don't find anything in the Knowledge Base Articles on Quest's Support site for Toad Edge. Probably a good idea to open a Support ticket with them, and provide them details (e.g. versions of MySQL and Joomla, steps to reproduce, etc.)